The invention relates to a hematology analyzer for counting and measuring the number of blood cells such as white blood cells and red blood cells in a blood sample or the like.
A method of counting and measuring white blood cells and red blood cells in blood with a hematology analyzer generally involves the use of an electric resistance detection system and the processes of measuring white blood cells while diluting the blood by 1/200 and of measuring red blood cells while diluting the blood further by 1/200 to prepare a 1/40000 diluted blood solution.
FIG. 14 shows a configuration of a conventional hematology analyzer. An aperture tube 80, which is disposed in a measuring cup 81, measures white blood cells, while an aperture tube 82, which is disposed in a measuring cup 83, measures red blood cells and the like. Between diluting cups 84, 85 and the measuring cups 81, 83 are auxiliary chambers 86, 87 for supplying solutions, with tubes 90, 91, each having a solenoid valve along its tube path, coupling between the diluting cups 84, 85 and the auxiliary chambers 86, 87, and between the auxiliary chambers 86, 87 and the measuring cups 81, 83, respectively. This hematology analyzer further includes a sampling nozzle 92 that absorbs not only patient's whole blood which will serve as a sample, but also diluted blood.
As shown in FIG. 15, to count and measure blood cells with such a hematology analyzer, a predetermined amount of blood is first collected from a sampling cup 93 by the sampling nozzle 92, then discharged into the diluting cup 84 (on the right) and diluted by 1/200 while simultaneously pouring a diluting solution from the sampling nozzle 92.
Thereafter, as shown in FIGS. 16, 17, the 1/200 diluted blood is drawn from the diluting cup 84 by the sampling nozzle 92, discharged into the diluting cup 85 (on the left), and diluted to 1/40000 with a diluting solution introduced from the sampling nozzle 92.
Successively, the auxiliary chambers 86, 87 are evacuated or emptied by a negative pressure by pumps, and the solenoid valves 88 are opened to transfer the diluted blood solutions in the diluting cups 84, 85 into the auxiliary chambers 86, 87 as shown in FIG. 18. At this point, a hemolysing reagent is injected into the auxiliary chamber 86 to destroy red blood cells. Then, the solenoid valves 88 are closed and the solenoid valves 89 are opened, and by pressuring the auxiliary chambers 86, 87 using a positive pressure, the diluted blood solutions in the auxiliary chambers 86, 87 are transferred to the measuring cups 81, 83 as shown in FIG. 19. Thereafter, the white blood cells are measured by the aperture tube 80 of the measuring cup 81, while the red blood cells and the like are measured by the aperture tube 82 of the measuring cup 83. After the measurement has been completed, the solenoid valves 94 are opened, the diluted blood solutions are discharged, and the cups 81, 83 are internally cleaned.
The above-mentioned conventional hematology analyzer requires not only the use of auxiliary chambers 86, 87 and pneumatic sources such as pumps, but also the use of tubes 90, 91 having solenoid valves 88, 89 to supply the solutions from the diluting cups 84, 85 to the measuring cups 81, 83. Such construction may occasionally cause defective supply of the solutions due to leakage from and clogging of the tubes 90, 91. The complicated structure of the system is another problem.